https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65136
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |missed-optimization
Status|UNCONFIRMED |ASSIGNED
Last reconfirmed| |2015-02-20
Version|unknown |5.0
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
Ever confirmed|0 |1
--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
The issue is that VRP constant-propagates into the latch edge PHI argument
which makes it unable to coalesce across the latch edge. It is also very
hard to undo this equivalence.
I have a patch.
